This invention relates to a method for mounting an object and a spindle device, and more particularly relates to a method of mounting an object that is more suitably used in a machine tool capable of performing high-precision processing, and to a spindle device.
In the spindle device utilized on a machine tool, a prescribed process is performed by mounting an object such as a tool or a work piece to a main shaft of the spindle device and by rotating it. It is to be noted that negative pressure is sometimes utilized when mounting the object to the main shaft (See Patent Document 1). In this case, positioning of the main shaft and the object is important in order to perform high-precision processing, but mounting in which negative pressure is utilized has merit in that adjusting the position of the main shaft and the object is comparatively easy even after the mounting.
[Patent Document 1] Japanese Patent Application Laid-Open 2002-224924 Publication
There have been attempts to rotate the main shaft at higher speeds in order to increase processing efficiency. It has become clear that in this case, when the object is mounted to the main shaft using negative pressure, it is possible that the object may shift during the processing due to the centrifugal force. In order to solve this problem, the object may be fixed to the main shaft using bolts, but when the object is fixed with bolts, it is difficult to adjust the position of the main shaft and the object after the fixing.
Further, in the case where the object is mounted to the main shaft using negative pressure, there is a problem of how to generate negative pressure for the rotatable main shaft. In Patent Document 1, the suction holes which are formed on the main shaft and are communicated with the suction holes in the housing are suctioned from outside thought a chuck. Thus, in the configuration of Patent Document 1, in the case where the main shaft decenters with respect to the housing and deforms due to thermal expansion, there is concern that the inner peripheral surface of the housing may contact the outer peripheral surface of the main shaft.